Topological heavy fermion model as an efficient representation of atomistic strain and relaxation in twisted bilayer graphene

The flat band physics of twisted bilayer graphene has been elucidated by its mapping to a heavy-fermion problem, but experiments have repeatedly shown the importance of strain and particle-hole symmetry breaking in the phase diagram. The authors show here that these ubiquitous effects can be incorporated as a handful of new terms in the Anderson model, preserving its heavy-fermion character.